Biphenylyl phosphoroamidothioates



2,875,234 BIPHENYLYL PHOSPHOROAMIDOTHIOATES Kenneth C. Kauer and Edgar C. Britten, Midland, Mich, assignors to The Dow Chemical Company, Midland, Mich., a corporation of' Delaware No Drawing. Application October 5, 1956 Serial No. 614,056

Claims. (Cl. 260-461) with the biphenylyl phosformula This invention is concerned phoroamidothioates having the NHY Inthis and succeeding formulas, X represents hydrogen,

chlorine or bromine, Y represents hydrogen, methyl or ethyl, and R represents methoxy, ethoxy or NHY. These new compounds are viscous, liquids or crystalline solids somewhat soluble in many organic solvents and of very low solubility in water.. They have been found to be active as, parasiticide s and are adapted to be employed.

as active toxic constituents of compositions for the control of mites and insect organisms such as aphids, flies and Mexican bean beetles.

The new compounds may be' prepared by reacting a phosphorocbloridothioatc of the formula wherein Z represents methoxy, ethoxy or chlorine with aqueous or gaseous ammonia, methylamine or ethylamine. The reaction is carried out in the presence of an inert organic solvent such as acetone or methylene chloride. The reaction is somewhat exothermic and takes place smoothly at temperatures of from" -l0 to 30 C. with the formation of the desired product and ammonium chloride or amine hydrochloride of reaction. The temperature may be controlled by regulating the rate of contacting the reactants and by external cooling. Good results are obtained when employing at least two molecular proportions of ammonia, methylamine or ethylamine with each molecular proportion of the phosphorochloridothioate;

In carrying out the reaction, gaseous ammonia, methylamine or ethylamine is contacted withthe phosphorochloridothioate dissolved in the reaction solvent. In an alternative procedure, an aqueous solution of ammonia, methylamine or ethylamine is mixed and blended with the phosphorochloridothioate dissolved in the reaction solvent. In either case, the addition is carried out with stirring and at a temperature of from to 30 C. Upon completion of the reaction, the reaction mixture is washed with water or diluted with a water immiscible solvent and the solvent thereafter removed by evaporation or distillation under reduced pressure to obtain the desired product as a residue. 1

The following examples illustrate the invention but are not to be construed as limiting.

ICC

. 2 Example I.0-(2-chloro-4-biphenylyl) O-methyl phosphoroamidothioate OCH:

Thirty grams of a. 25 percent aqueous solution of am-- monia Was added portionwise with stirring to a solution of 66.6 grams (0.2 mole) of O-(.2-chloro-4-biphenylyl)" O-methyl phosphorochloridothioate dissolved in 200 milliliters of methylene chloride. The addition was carried out over a period of 30 minutes and at a temperature of from 5 to 12 for 2 hours while. the temperature was allowed to rise to 27 C. Upon completion of the reaction, the reaction:

mixture was washed with water and the methylene chloride removed by distillation under reduced pressure to obtain an O-(2-chloro-4-biphenylyl) O-methyl phosphoroamidothioate product as a viscous" liquid residue. This product had a refractive index MD of 1.6356 at 25 C. and contained 9.26 percent phosphorus and 10.04

percent sulfur compared to the calculated values of 9.9

percent and 11.2 percent, respectively.

Example 2.0-(3-biphenylyl) O-methyl phosphoroamidothiaate OOH;

Thirtygrams' of a 25 percent aqueous solution of ammonia was added gradually with stirring to 60 grams (0.2 mole) of O-(3-biphenylyl) O-methyl phosphorochloridothioate dissolved in milliliters of acetone. The addition was carried out over a tively.

Example 3.-O-(2-biphenylyl) O-methyl phrosphoroamidothioate TS; OOHs 4 This compound was prepared in the same manner and under the same temperature conditions as those described in Example 2 by the reaction of C-(Z-biphenylyl) 0- methyl phosphorochloridothioate and aqueous ammonia. Upon completion of the reaction, the reaction mixture was processed as previously described to obtain the de sired product as a viscous, yellow liquid having a refractive index n/D of 1.6069 at 25 C. and a density of 1.243 at 25 C. This product contained 10.96 percent sulfur and 4.89 percent nitrogen compared to the calcu- C. Stirring was thereafter continuedlateel values of 11.45 percent and 5.02 percent, respective y.

Example 4.---(2 bromo-4-liiphenylyl) phosphorodiami- 'dothioate I i l S NHB 20: C. During :the reaction, an O-.(2-bromo-4-biphen-.i

ylyl) phosphorodiamidothioate product precipitated in the reaction mixture as a crystalline solid. This product waszseparated byfiltration, washed with water, and thereafter recrystallized from ethanol. The recrystallized product melted at 120-l22 C. andcontained 8.74 percent phosphorus and 9.80 percent sulfur compared tothe theoretical values of 9.05 percent and 9.34 percent;

respectively.

Example .0-(2-chloro-4-biphenylyl) 0-ethyl-N-meth-- yl phosphoroamidothioute '7 One mole of methylamine as a 25 percent aqueous solution is added portionwise with stirring to 0.5 mole of O-(2-chloro-4-biphenylyl) O-ethyl phosphorochloridothioate dissolved in 300 milliliters of acetone. The methylamine is added over a period of one hour and at a temperature of C. When the addition is complete, the reaction mixture is processed as described in Example 1 to obtain the desired product as a liquid residue having a molecular weight of 341.

In a similar manner other biphenylyl phosphoroamidothioates may be prepared as follows:

O-(Z-biphenylyl) O-methyl N-ethyl phosphoroamidothioate by the reaction of ethylamine with O -(2-biphenylyl) O-methyl phosphorochloridothioate.

. O-(3-biphenylyl) phosphorodiamidothioate by the reaction of ammonia with O-(3-biphenylyl) phosphorodichloridothioate.

O-(2-bromo-4 biphenylyl) O-methyl N-methyl phosphoroamidothioate by the reaction of methylamine with O-(2-bromo-4-biphenylyl) O-methyl phosphorochloridothioate. i

O-(2-chloro-6 biphenylyl) O-ethyl N-ethyl phosphoro- 'amidothioate by the reaction of ethylamine with O-(Z- chloro-fi-biphenylyl) O-ethyl phosphorochloridothioate. O-(2-chloro-4-biphenylyl) phosphoroamidothioate by the reaction of ammonia with 0-(2-ch1oro-4-biphenylyl) phosphorodichloridothioate.

,. asman. i

O-(Z-biphenylyl) N,N'-diethyl phosphoroamidothioate 'by the reaction of ethylamine with O-(4-biphenylyl) phosphorodichloridothioatej The new biphenylyl phosphoroamidothioates of the present invention are effective as parasiticides and are adapted to be employed for the control of numerous household and agricultural pests. For such use the products maybe dispersed'on a finely divided carrier and employed as dusts. The new products may also. beemployed.

in oils, as constituents 'in wateremulsious or in waterdispersions. In representative operations, 100'perceutcontrols of bean aphids and houseflies have been obtained with aqueous compositions containing 10.0 parts by. weight of O-(3-biphenylyl) O-methylphosphoroamidothioate portionwise to the O-biphenylyl' phosphorodichlorido thioate at a temperature of 40 to 50 C. and under-con ditions of reduced pressure in the reaction mixture. Following the reaction, the reaction mixture is partially distilled under reduced pressure toremove low boiling constituents and obtain the desired product as a crystal formula per million parts of ultimate mixture.

The O-biphenylyl O-methyl" phosphorochloridothioates and O-biphenylyl O-ethyl phosphorochloridothioates employed as starting materials.in the present invention. may be prepared by reacting from 2 'to 3 molecular lprop'ortions of methanol'or ethanol with one molecular propor tion of an O-biphenylyl phosphorodichloridothioate at a temperature at which hydrogen chloride is formed as a product of reaction while continuously withdrawing hydrogen chloride in the gaseous state from the reaction mixture as formed, said temperature being at least 15 centigrade degrees below the boiling point at 760 millimeters pressure of methanol or ethanol. In carrying out the reaction, the methanol "or ethanol maybe added line or liquid residue.

- We claim:

1. A biphenylyl NHY in which X represents a member of the group consisting phosphoro? 4. O-(3-biphenylyl) O-methyl phosphoroamidothioate; 5. O-(Z-biphenylyl) O-methyl phosphoroamidothioatej References Cited in the file of this patent UNITED STATES PATENTS 2,033,918 Britton Mar. 17, 1936, 2,506,344 ,Cleary May 2, 1950 FOREIGN PATENTS i 814,152 Great Britain .4... Sept. 20, 1951,

phosphoroamidothioate having the group consisting of 

1. A BIPHENYLYL PHOSOHOROAMIDOTHIOATE HAVING THE FORMULA 